The runtime now discovers both legacy and current Claude config files at
user and project scope, merges them in precedence order, and carries the
resolved model, permission mode, instruction files, and MCP server
configuration into session startup.
This keeps CLI defaults aligned with project policy and exposes configured
MCP tools without requiring manual flags.
Constraint: Must support both legacy .claude.json and current .claude/settings.json layouts
Constraint: Session startup must preserve CLI flag precedence over config defaults
Rejected: Read only project settings files | would ignore user-scoped defaults and MCP servers
Rejected: Delay MCP tool discovery until first tool call | model would not see configured MCP tools during planning
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Keep config precedence synchronized between prompt loading, session startup, and status reporting
Tested: cargo fmt --all --check; cargo clippy --workspace --all-targets --all-features -- -D warnings; cargo test --workspace --all-features
Not-tested: Live remote MCP servers and interactive REPL session startup against external services
Add typed runtime-facing MCP and OAuth configuration models on top of the existing merged settings loader so later parity work can consume validated structures instead of ad hoc JSON traversal.
This keeps the first slice bounded to parsing, precedence, exports, and tests. While validating the slice under the repo's required clippy gate, I also fixed a handful of pre-existing clippy failures in runtime file operations so the requested verification command can pass for this commit.
Constraint: Must keep scope to parity-unblocking primitives, not full MCP or OAuth flow execution
Constraint: cargo clippy --all-targets is a required verification gate for this repo
Rejected: Add a new integrations crate first | too much boundary churn for the first landing slice
Rejected: Leave existing clippy failures untouched | would block the required verification command for this commit
Confidence: medium
Scope-risk: moderate
Reversibility: clean
Directive: Keep future MCP/OAuth additions layered on these typed config surfaces before introducing transport orchestration
Tested: cargo fmt --all; cargo test -p runtime; cargo clippy -p runtime --all-targets -- -D warnings
Not-tested: workspace-wide clippy/test beyond the runtime crate; live MCP or OAuth network flows
